1. Field of the Invention
The present invention relates to a disc recliner mechanism for automotive seating with reduced backlash. More specifically, the present invention relates to a disc recliner mechanism which achieves a reduced backlash without requiring additional manufacturing steps.
2. Description of Related Art
Many automotive seats have a seat back whose position, relative to a seat base, can be altered by a vehicle occupant for comfort positioning and/or to provide access to an interior of a vehicle. Disc recliner mechanisms are commonly employed to provide the relative movement between the seat back and the seat base and such disc recliner mechanisms often include a tooth plate and a guide plate, the latter of which includes a set of pawls that can selectively interlock with the tooth plate to maintain the seat back in a desired position.
Typically, the tooth plate portion of the disc recliner mechanism is affixed to the seat back and the guide plate portion of the disc recliner mechanism is affixed to the seat base, although the mechanism can also be mounted in the opposite sense.
While such disc recliner mechanisms are well known and are widely employed, they do suffer from disadvantages. In particular, once the seat back is set in a desired position, any movement of the pawls resulting from excessive clearances between the pawls and guides on the guide plate will result in undesired movement of the seat back with respect to the seat base. Such undesired movement of a positioned seat is typically referred to as “backlash” or “chuck.”
To avoid undesired backlash, the pawls and guide plate must be formed to extremely tight tolerances, either directly when the guide plate is formed, or via additional manufacturing steps after the guide plate has been formed. As is apparent to those of skill in the art, meeting such extremely tight manufacturing tolerances or performing additional manufacturing steps both result in increased expense and a desired reduction in backlash may still not be achieved.
It is desired to have a disc recliner mechanism that has reduced or negligible backlash and which can be manufactured at a reasonable cost.